uclient-example.c

   1 /*
   2  * uclient - ustream based protocol client library
   3  *
   4  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <dlfcn.h>
  22 #include <getopt.h>
  23 #include <fcntl.h>
  24
  25 #include <libubox/blobmsg.h>
  26
  27 #include "uclient.h"
  28
  29 #ifdef __APPLE__
  30 #define LIB_EXT "dylib"
  31 #else
  32 #define LIB_EXT "so"
  33 #endif
  34
  35 static struct ustream_ssl_ctx *ssl_ctx;
  36 static const struct ustream_ssl_ops *ssl_ops;
  37 static int quiet = false;
  38 static bool verify = true;
  39 static const char *output_file;
  40 static int output_fd = -1;
  41 static int error_ret;
  42
  43 static int open_output_file(const char *path, bool create)
  44 {
  45         const char *str;
  46         char *filename;
  47         int len;
  48         int flags = O_WRONLY;
  49
  50         if (create)
  51                 flags |= O_CREAT;
  52
  53         if (output_file) {
  54                 if (!strcmp(output_file, "-"))
  55                         return STDOUT_FILENO;
  56
  57                 return open(output_file, flags, 0644);
  58         }
  59
  60         /* Don't automatically overwrite files if the name is derived from the URL */
  61         if (create)
  62                 flags |= O_EXCL;
  63
  64         len = strcspn(path, ";&");
  65         while (len > 0 && path[len - 1] == '/')
  66                 len--;
  67
  68         for (str = path + len - 1; str >= path; str--) {
  69                 if (*str == '/')
  70                         break;
  71         }
  72
  73         str++;
  74         len -= str - path;
  75
  76         if (len > 0) {
  77                 filename = alloca(len + 1);
  78                 strncpy(filename, str, len);
  79                 filename[len] = 0;
  80         } else {
  81                 filename = "index.html";
  82         }
  83
  84         return open(filename, flags, 0644);
  85 }
  86
  87 static void request_done(struct uclient *cl)
  88 {
  89         if (output_fd >= 0 && !output_file) {
  90                 close(output_fd);
  91                 output_fd = -1;
  92         }
  93         uclient_disconnect(cl);
  94         uloop_end();
  95 }
  96
  97 static void example_header_done(struct uclient *cl)
  98 {
  99         static int retries;
 100
 101         struct blob_attr *cur;
 102         int rem;
 103
 104         if (retries < 10 && uclient_http_redirect(cl)) {
 105                 if (!quiet)
 106                         fprintf(stderr, "Redirected to %s on %s\n", cl->url->location, cl->url->host);
 107
 108                 retries++;
 109                 return;
 110         }
 111
 112         retries = 0;
 113         if (!quiet) {
 114                 fprintf(stderr, "Headers (%d): \n", cl->status_code);
 115                 blobmsg_for_each_attr(cur, cl->meta, rem) {
 116                         fprintf(stderr, "%s=%s\n", blobmsg_name(cur), (char *) blobmsg_data(cur));
 117                 }
 118         }
 119
 120         switch (cl->status_code) {
 121         case 204:
 122         case 200:
 123                 output_fd = open_output_file(cl->url->location, true);
 124                 if (output_fd < 0) {
 125                         if (!quiet)
 126                                 perror("Cannot open output file");
 127                         error_ret = 3;
 128                         request_done(cl);
 129                 }
 130                 break;
 131
 132         default:
 133                 request_done(cl);
 134                 error_ret = 8;
 135                 break;
 136         }
 137 }
 138
 139 static void example_read_data(struct uclient *cl)
 140 {
 141         char buf[256];
 142         int len;
 143
 144         if (output_fd < 0)
 145                 return;
 146
 147         while (1) {
 148                 len = uclient_read(cl, buf, sizeof(buf));
 149                 if (!len)
 150                         return;
 151
 152                 write(output_fd, buf, len);
 153         }
 154 }
 155
 156 static void msg_connecting(struct uclient *cl)
 157 {
 158         char addr[INET6_ADDRSTRLEN];
 159         int port;
 160
 161         if (quiet)
 162                 return;
 163
 164         uclient_get_addr(addr, &port, &cl->remote_addr);
 165         fprintf(stderr, "Connecting to %s %s:%d\n", cl->url->host, addr, port);
 166 }
 167
 168 static void init_request(struct uclient *cl)
 169 {
 170         uclient_connect(cl);
 171         msg_connecting(cl);
 172         uclient_http_set_request_type(cl, "GET");
 173         uclient_request(cl);
 174 }
 175
 176 static void example_eof(struct uclient *cl)
 177 {
 178         request_done(cl);
 179 }
 180
 181 static void handle_uclient_error(struct uclient *cl, int code)
 182 {
 183         const char *type = "Unknown error";
 184         bool ignore = false;
 185
 186         switch(code) {
 187         case UCLIENT_ERROR_CONNECT:
 188                 type = "Connection failed";
 189                 error_ret = 4;
 190                 break;
 191         case UCLIENT_ERROR_SSL_INVALID_CERT:
 192                 type = "Invalid SSL certificate";
 193                 ignore = !verify;
 194                 error_ret = 5;
 195                 break;
 196         case UCLIENT_ERROR_SSL_CN_MISMATCH:
 197                 type = "Server hostname does not match SSL certificate";
 198                 ignore = !verify;
 199                 error_ret = 5;
 200                 break;
 201         default:
 202                 error_ret = 1;
 203                 break;
 204         }
 205
 206         if (!quiet)
 207                 fprintf(stderr, "Connection error: %s%s\n", type, ignore ? " (ignored)" : "");
 208
 209         if (ignore)
 210                 error_ret = 0;
 211         else
 212                 request_done(cl);
 213 }
 214
 215 static const struct uclient_cb cb = {
 216         .header_done = example_header_done,
 217         .data_read = example_read_data,
 218         .data_eof = example_eof,
 219         .error = handle_uclient_error,
 220 };
 221
 222 static int usage(const char *progname)
 223 {
 224         fprintf(stderr,
 225                 "Usage: %s [options] <URL>\n"
 226                 "Options:\n"
 227                 "       -q:                             Turn off status messages\n"
 228                 "       -O <file>:                      Redirect output to file (use \"-\" for stdout)\n"
 229                 "\n"
 230                 "HTTPS options:\n"
 231                 "       --ca-certificate=<cert>:        Load CA certificates from file <cert>\n"
 232                 "       --no-check-certificate:         don't validate the server's certificate\n"
 233                 "\n", progname);
 234         return 1;
 235 }
 236
 237
 238 static void init_ustream_ssl(void)
 239 {
 240         void *dlh;
 241
 242         dlh = dlopen("libustream-ssl." LIB_EXT, RTLD_LAZY | RTLD_LOCAL);
 243         if (!dlh)
 244                 return;
 245
 246         ssl_ops = dlsym(dlh, "ustream_ssl_ops");
 247         if (!ssl_ops)
 248                 return;
 249
 250         ssl_ctx = ssl_ops->context_new(false);
 251 }
 252
 253 static int no_ssl(const char *progname)
 254 {
 255         fprintf(stderr, "%s: SSL support not available, please install ustream-ssl\n", progname);
 256         return 1;
 257 }
 258
 259 enum {
 260         L_NO_CHECK_CERTIFICATE,
 261         L_CA_CERTIFICATE,
 262 };
 263
 264 static const struct option longopts[] = {
 265         [L_NO_CHECK_CERTIFICATE] = { "no-check-certificate", no_argument },
 266         [L_CA_CERTIFICATE] = { "ca-certificate", required_argument },
 267         {}
 268 };
 269
 270 int main(int argc, char **argv)
 271 {
 272         const char *progname = argv[0];
 273         struct uclient *cl;
 274         int ch;
 275         int longopt_idx = 0;
 276
 277         init_ustream_ssl();
 278
 279         while ((ch = getopt_long(argc, argv, "qO:", longopts, &longopt_idx)) != -1) {
 280                 switch(ch) {
 281                 case 0:
 282                         switch (longopt_idx) {
 283                         case L_NO_CHECK_CERTIFICATE:
 284                                 verify = false;
 285                                 break;
 286                         case L_CA_CERTIFICATE:
 287                                 if (ssl_ctx)
 288                                         ssl_ops->context_add_ca_crt_file(ssl_ctx, optarg);
 289                                 break;
 290                         default:
 291                                 return usage(progname);
 292                         }
 293                         break;
 294                 case 'O':
 295                         output_file = optarg;
 296                         break;
 297                 case 'q':
 298                         quiet = true;
 299                         break;
 300                 default:
 301                         return usage(progname);
 302                 }
 303         }
 304
 305         argv += optind;
 306         argc -= optind;
 307
 308         if (argc != 1)
 309                 return usage(progname);
 310
 311         if (!strncmp(argv[0], "https", 5) && !ssl_ctx)
 312                 return no_ssl(progname);
 313
 314         uloop_init();
 315
 316         cl = uclient_new(argv[0], NULL, &cb);
 317         if (!cl) {
 318                 fprintf(stderr, "Failed to allocate uclient context\n");
 319                 return 1;
 320         }
 321
 322         if (ssl_ctx)
 323                 uclient_http_set_ssl_ctx(cl, ssl_ops, ssl_ctx, verify);
 324
 325         init_request(cl);
 326         uloop_run();
 327         uloop_done();
 328
 329         uclient_free(cl);
 330
 331         if (output_fd >= 0 && output_fd != STDOUT_FILENO)
 332                 close(output_fd);
 333
 334         if (ssl_ctx)
 335                 ssl_ops->context_free(ssl_ctx);
 336
 337         return error_ret;
 338 }